It's easy (and perhaps intuitive) to say things like "tax-exempt groups shouldn't be allowed to engage in political activity" or "education produces positive externalities and should therefore be subsidized." But what is "political activity"? What is "education"? My definitions may be very different from yours. Paying the armies of lawyers necessary to work this out might actually cost more than the purported benefits of the restriction or the subsidy, and these aren't terms with objective definitions that lie waiting to be discovered. They are constantly in flux, with new types of political activity and education emerging as people come up with ever-more creative responses to the world around them. They are defined in the process of their emergence.
I've visited Buchanan a few times elsewhere, here and here. A question for the readers:
What are other examples of phenomena, products, organizations, or ideas that are defined in the process of their emergence?